I can see a valid argument for allowing mods like this if the desire is for FAF to be primarily about what decisions you make, and for high apm to play as reduced a role as possible. However, this means that various other currently banned things like auto-clickers and auto-manual reclaim should be allowed. Essentially any automated micro should be permissible.
The alternative is that high apm activities are for the most part not considered appropriate to automate beyond UI type options (e.g. selection based hotkeys that selects certain units at the press of a button) and basic quality of life enhancements (right clicking a mex to build storage around it). For the most part this seems the route FAF has taken.
Therefore as things currently stand it doesn't make sense to me that a mod is allowed that automatically takes actions for you (enabling and disabling mass fabs based on your current energy requirements), but other mods such as the autoclickers and reclaim are banned. I'd therefore favour banning this aspect of EcoManager, regardless of whether such functionality is considered good or not (as many people have commented in the past about how relying on this functionality can teach you bad habits and make you a worse player).